What are the possible causes of ptosis accompanied by convulsive seizures?

Causes of Ptosis with Convulsions

When ptosis presents with convulsive seizures, the most critical diagnosis to consider is botulism, which causes descending paralysis with cranial nerve dysfunction (including ptosis) and can trigger seizures through severe metabolic derangement, though myasthenia gravis with myasthenic crisis represents another life-threatening neuromuscular junction disorder that can present similarly. 1

Toxin-Mediated Causes

Botulism

• Botulinum neurotoxin causes cranial nerve dysfunction including ptosis (droopy eyelids), diplopia, and photophobia, followed by descending paralysis 1
• The toxin blocks acetylcholine release at the neuromuscular junction, causing both the characteristic ptosis and potential seizures secondary to respiratory failure and metabolic derangement 1
• Symptoms are dose-dependent and include bulbar nerve dysfunction (dysarthria, dysphonia, dysphagia) alongside the ptosis 1
• This represents a medical emergency requiring immediate supportive care and antitoxin administration 1

Neuromuscular Junction Disorders

Myasthenia Gravis with Crisis

• Variable, fatigable ptosis that worsens with prolonged upgaze and improves with rest is pathognomonic for myasthenia gravis 2, 3
• Patients with neck drop, dysphagia, dysarthria, or difficulty breathing require ICU-level monitoring for impending respiratory failure 3
• Myasthenic crisis can lead to seizures through severe hypoxia and metabolic derangement 3
• The ice pack test (2 minutes over closed eyes) showing approximately 2 mm reduction in ptosis is highly specific for myasthenia gravis 2, 3, 4
• 50-80% of patients with ocular myasthenia progress to generalized disease within a few years 2, 3

Structural Neurogenic Causes with Seizures

Third Nerve Palsy with Compressive Lesions

• Pupil-involving third nerve palsy with ptosis requires urgent MRI with gadolinium plus MRA or CTA to rule out posterior communicating artery aneurysm—a neurosurgical emergency 2, 4
• Compressive tumors (meningioma, schwannoma, metastatic lesions) can cause both ptosis and seizures 2
• Do not assume pupil-sparing indicates benign microvascular disease when ptosis is incomplete or ophthalmoplegia is partial—compressive lesions can present this way 2

Structural Brain Lesions

• Seizures are associated with structural brain lesions including tumors, infection, infarction, traumatic brain injury, vascular malformations, and developmental abnormalities 1
• These same lesions can cause ptosis through direct compression of cranial nerve III or involvement of supranuclear pathways 2, 5

Infectious and Inflammatory Causes

Meningitis and Encephalitis

• Leptomeningeal disorders and infectious meningitis can cause ptosis 2
• Encephalitis viruses cause seizures, confusion, and paralysis, which can include cranial nerve involvement with ptosis 1
• Infectious diseases including syphilis and Lyme disease can cause both ptosis and seizures 2, 5

Metabolic and Toxic Encephalopathies

• Wernicke's encephalopathy and botulism may be accompanied by ptosis and can trigger seizures through metabolic derangement 5
• Diabetes mellitus can cause both microvascular third nerve palsy (with ptosis) and metabolic seizures 5

Critical Diagnostic Algorithm

Immediate Assessment

1. Check for neck drop, dysphagia, dysarthria, or difficulty breathing—these indicate generalized myasthenia requiring ICU monitoring 3
2. Examine pupils in bright and dim illumination—anisocoria or mydriasis with ptosis indicates pupil-involving third nerve palsy requiring urgent MRA or CTA 3, 4
3. Measure vital capacity and negative inspiratory force immediately if any bulbar or respiratory symptoms are present 3

Diagnostic Testing

• Perform ice pack test: 2 minutes over closed eyes, with ≥2 mm improvement highly specific for myasthenia gravis 2, 3, 4
• Order acetylcholine receptor antibody testing (80-88% sensitivity for generalized myasthenia, 98-100% specificity) 3
• Urgent neuroimaging (MRI with gadolinium and MRA or CTA) for any pupil-involving ptosis or acute onset with severe headache 2, 4
• Consider lumbar puncture for suspected infectious meningitis or encephalitis 4

Common Pitfalls to Avoid

• Do not dismiss ptosis with normal pupil as benign—partial third nerve palsy or seronegative myasthenia can present this way 3
• Do not overlook variable ptosis that worsens with fatigue, pathognomonic for myasthenia gravis 3
• Do not delay respiratory assessment in patients with neck drop or bulbar symptoms—myasthenic crisis can be life-threatening 3
• Missing pupil-involving third nerve palsy as a neurosurgical emergency (aneurysm) can be fatal 2